Percussive rock drill and the like



Aug. 28, 1923.

R.DE H.ST.STEPHENS ET AL PERQUSSIVE ROCK.DRILL AND THE LIKE Filed April 26, 1921 Patented Aug. 28, 1923.

warren RAYNAR DE HELE 'ST. STEPHENS, CAJQBDBNE, AND ALFRED EWIhTG, OF LONDON,

" ENGLAND.

rnnoossrvn nocrz'nnrnri AND THE LIKE.

Application filed April as, 1921. Serial No. 464,598.

To all whom it may concern.

Be it known that we, RAYNAR n'n Hnnn Sr. STEPHENS, of Homefield, Gamborne, Cornwall, England, and .ALrRno' EwINe, oii4 Broad Street Place, London E.' 2, Eng land, both subjects of the -King of Great Britain, have invented certain new and useful Improvements in Percussive Rock Drills and the like, of which the following is a specification.

.This invention relates'to percussive rock d'rills and the like wherein water is conveyed drilled, and to prevent the formation of dust and so forth. It is the object of this invention to improve the construction or such drills particularly in regard to the feed of water by preventing any admixture of air with 'the' water, so that atomization or spraying is prevented, and the flushing out of the hole by the wateris renderedmoreefficient. In the improved]constructionaccording to this invention the tube conveying the water to the drill steel is arranged coaxially with the drill steel and the .piston, and is held fixed inthe anvilblock 'into which the head of the drill steel'fits, while the piston slides over the tube, and the end of the tube beyond the piston works through packing in a gland. With this construction the water flows through a closed tubular path to the drill steel, and any entrance of air into the tube, or leakage or water therefrom is prevented. I In the accompanying drawing: or Figure l is a longitudinal section-o1" a percussive rock drill provided with the water supplying means according to the inven tion.

Figure 2 is a section on the line A 413 of Figure 1. Y Figure 3 is a section on the line'G'-D of Figure 1, and V Figurei4 is Figure 1. 7

It will'be convenient todescribe the invention as applied to a'percu'ssi've rock drill a section on thexlin'e of of'aknown. type wherein a pneumatically. Y v I .blo'ck11, Thebore 290i the drill steel 12 operatedpiston l-workingin abylinder 2 has a rod 3' or extens on 3 formed with sp ral grooves at 4 which engage with a nut formed internally in'the member 5. This member 5 1s prevented from rotation on the forward movement of the piston 1 by means of spring actuated 'pawls 6, Figure 4,. engagingwith the toothed rim thereof. ,At itsi'orward end the .rod '3 is provided at -7 with straight grooves with which are adapted to engage castellations or ribsS formed in a nut 9.

This nut is screwed into the bush 10 which head of the" drill steel 12.

a In adrill of this character the anvil block 2 l1which fits by castellations 13 or otherwise into grooves in the-rotating'bush 10, has the forward end ofthe tube 14 conveying the water securely held therein. Forthis purpose the anvil block 11is drilledthrough from the rear and has a conical recess at 15 therein in which is fitted a thick tapering washer 16 of rubberor the like whichcholds the tube 14 securely but resiliently. LThe water tube 14 is passed lthroughthis rubber washer 16 so that its" head 17. bears against the same, and the tube 14 is thus packed in a fluid-tight manner in the anvil block 11. The tube 14 projectsrearwardly from the anvil block. 11 through the central bore'18 of the piston. rod 3 and the piston 1 and into a stufiing box 19 in the handle section 20 of the tool. In this stufiing box is a gland 21 with suitable packing material 22 through whichthe tube 14 can slide in a fluid-tight manner. The end of thestnfiing boX 22 is accommodates the anvil block 11 and'the closed by a suitable cap 23 which is adapted to screw over the end of the gland 21$ Water is conveyed to the inner end of the gland.

21 by an inclined passage way vformed at 24 therein, thls passageway leading toa lateral passage at 25 in the handle portion 20 communicating with a socket 26 to which 7 At the forward end of the anvil block 11 isa conicalor tapering recess into which thetapered end ofthe drill steel 12 fits, thus making a water-tight joint with the for the passagefo'i water thus comes opposite the pawls 6.

to the end 01"- the tube lt fixed in the anvil block 11 and as there is no relative movement' betweenthese parts while the drill is in use, the short at 30 between the end of the tube let and the bore 29 of the; drill steel 12 becomes tilled with wateiyso't-hat a continuous flow o f water from the tubele through the drill steel 12 and the drill bit can be maintained. No air can' become intermingled with the water and atomization is thus effectively prevented. The "flow of drill steel may be rotated by the anvil block 11 by means or" the tapered portion 28 or" its shank fitting therein. drill steel 12 may be mauesquare and may pass as shown through a tool holder 31 mounted in the rotating bush 10, this tool holder having a square hole broached through it, and being formed externally with castellations 32 or otherwise for engagement with the rotating bush 10 while allowing of longitudinal reciprocating movement The operation of a percussive rock drill as hereinbetore described is as tollowsz- The pistonrl is operated in the usual manner by compressed air of which the passage into the cylinder 2 is controlled by a valve 33 in the well known manner. On the forward movement of the piston 1 the nut 5 will be allowed to turn by the pawls 6 so that the piston will carry out its forward stroke without turning itself or the sleeve 10; Towards the end of the forward movement the piston rod 8' will strike the anvil block 11 and thus impart ablow to the drill steel 12. On the return stroke of the piston 1, the piston will be turned as its grooves 4 engage with the nut inside the member 5 which is prevented from turning The forward end of the piston rod 3 which engages with the nut 9,

willthus turn the nut 9 and consequently also the sleeve 10, which in its turn rotates the anvil block 11 and the tool holder 31. On the succeeding strokes of the piston the operations described above will be repeated.

The invention is not limited in its application to any particular'ty'pe of percussive rill, but it can be applied to the drills and similar tools in which the movement is imparted to the steel bit 12 by pneumatic' or other mechanism the arrangement always being, such that the water tube 14; is held se 7 curely as by the rubber wa-sher 16v in the anvil block 11' or its equivalent into which the head 28 of the drill steel 12 fits, while the other end of the tube 1 slides through a gland allowing of longitudinal and rotating The shank of the the gland.

movement, the water being fed incontinuously to this end of the tube beyond the gland.

Having thus described our invention what iwe claim as new and desire to secure by Letters Patent is 1. he percussive rock 'drill comprising-a cylinder with a handle portion, a piston with a central bore adapted to work in said cylinder, means foneontrolling the supply of fluid for operating said piston, a drill steel having a central bore and a tapered head, said drill steel being mounted in said cylinder, an anvil block slidably mounted .in the cylinder between the piston and the drill steel and adapted to receive the'tapered head otthe drill steel, a stufling box and gland'in the handle portion, a tube passing concentricallythrough the anvil block and having one end secured thereto, said end being adjacent the central bore in the drill steel, said tube being adapted to slide through the central borec ot the piston, whilst its other end is adapted to slide through the gland, and means for supplying 7 liquid to the end of the tube sliding through '2. A pneumatiorock drill comprising a cylinder with a handle portion, a piston with a central bore working in said cylinder,

- means torcontrolling the supply of fluid for operating said piston, a drill steel having. a central bore and a tapered head, said drill steel being mounted in said cylinder,an anvil block with a central bore slidably mounted in said cylinder, said anvil block being provided with a conical recess merging into an underout recess in which thecentral bore terminates, theconicalrecess being aclapte d. to receive the tapered head of the drill steel, :1, thick tapered'washer in the/undercut recess,

a tube passing. through the central bore of the piston and the anvil block and having one end passing through a washer which holds the tube securely but. resiliently, .a packing gland in the handle portion through which the other end of said tube works, and means for supplying a liquid under pressure to the gland. p V

3. A pneumatic rock drill comprising a cylinder with a handle portion,. a piston with a central bore working in said cylinder means for controlling'the supply of flui for operating said piston, said piston having spiral grooves therein, axial ribs on said piston, a member having a toothed periphery mounted'in said cylinder, ribs on the inner surface of said member adapted to engage with the spiral grooves in the piston, a bush with nternal grooves mounted inthe cylinder, a nut screwing into the bush and having straight grooves in the interior thereof for engagement with the axial ribs on the piston ananvil block with .a central bore mounted in sald bush, ribs on said anvil block for engagement with the grooves in the bush, a stuffing box and gland in the handle portion, a tube passing through the anvil block and having. one end secured thereto, said end being adjacent the central bore in the drill steel, said tube being adapt ed to slide through the central bore of the piston, Whilst its other end is adapted to slide through the gland, and means for supplyingliquid to the end of the tube sliding through the gland.

4. A pneumatic rock drill comprising a cylinder with a handle portion at one end ing a rectangular portion for engagement With the rectangular hole in the tool holder,

said'drill steel having a central 'bore,- an

anvil block'with a central bore, ribs'on-said anvil block for engagement With the grooves in the bush, said anvil block-being provided with a conicalrecess emerg ng into an un-' dercutrecess 1n which the central bore termr' nates, the conical recess being adapted to receive the tapered head of the drill steel, a thick tapered Washer inthe undercut re.-

cess, a tube passing through the central bore of the piston and the anvil block and having one end passing through the Washer which holds the tube securely but resiliently, said tube having one end adjacent the central bore in the drill steel, a packing gland in the handle portion, the tube being adapted to pass through the central bore of the-piston and piston rod and Working in said packing gland,'a cap covering the end of thepacking gland, and means for supplying liquid under pressure to said gland.

RAYNAR de HELE ST.

' ALFRED EWING.

STEPHENS. 

